In the metalworking industry, power presses are often used to form stock material such as steel or sheet metal into a variety of components. For example, in the automotive industry, sheet stock is formed into components of relatively small parts, such as engine struts, as well as significantly larger vehicle body components, such as deck lids, doors, and quarter panels.
Typically, the workpiece is drawn or struck one or more times between upper and lower die halves to form the stock into a desired shape. Due to the particular shape of the article, in many applications, it is necessary to perform an operation on the workpiece at an angle other than with the travel of the press. For example, it may be necessary to punch an opening into or trim flash from the edge of the workpiece. In such situations, the workpiece may be reoriented and/or advanced to another workstation to perform the required operation. Alternately, a separate device may be provided within the particular workstation. Such devices may be actuated once the drawing has been completed, or, alternately, simultaneously with the drawing operation.
"Aerial cam" units are particularly effective devices for performing such auxiliary operations. These cam units are generally associated with the ram of the press. Thus, aerial cam units are suspended above the working area when the press is open and, consequently, do not interfere with the movement of a workpiece through the press. "Base mounted" cam units, however, can likewise perform these functions in an effective manner. Base mounted cam units, in contrast to aerial cam units, are generally secured to the press bed.
While various aerial and base mounted cam devices have been developed, each cam unit is generally unique to the die set, part, and press for which it has been designed. Thus, when the die set or part is changed on a press, the cam unit must likewise be changed. Consequently, a cam unit must be provided for each die set or part utilized in a particular press. The design and construction of unique cam units for use with the various die sets or parts utilized in a particular press is both costly and time consuming. Further, cam units are generally quite large, cumbersome, and heavy. Thus, replacing the unit can be difficult and time consuming, resulting in excessive downtime, high labor costs, and high maintenance costs.